This cover seals well and there's enough support in the middle. There was a small tear in a corner that I noticed after I unrolled the cover after installation. I can't be absolutely sure that I didn't somehow tear it myself trying to get the rails to seat against the roll frame, so could be on me. I have a 2016 Ram 1500 with a 6'4" bed. In order to get the cover to latch shut at the tailgate, I had to clamp the rails so that they actually pulled inside the bed sides by about half an inch when all was said and done. Got it to latch, but took a star for not being better sized for my truck. Otherwise, this cover works fine.